looking for an improved SAS function mod

[Skalou]

hello ,

I'm looking for a mod improving the SAS function, looked a bit in the forum but didn't find what i would like:

-tune parameters to not over compensate (or really less)

-automatic tuning depending of the ship: mass, inertia, sas torque...

with this i should be able to use "persistant rotation mod", dost it exist yet?

[Frostea]

The Smart A.S.S feature from Mechjeb is better than the stock when not in atmosphere, and it comes with a bunch of other utilities.

[wasml]

Not quite what you were looking for but a bit more realistic - [h=2](Semi-)Saturatable Reaction Wheels

[/h] http://forum.kerbalspaceprogram.com/threads/111049

[monstah]

MechJeb has an "attitude ajustment" window, where you can set some of its parameters, but AFAIK it's not a per-ship setting, and definetely not automatic based on mass.

[StahnAileron]

hello ,

I'm looking for a mod improving the SAS function, looked a bit in the forum but didn't find what i would like:

-tune parameters to not over compensate (or really less)

-automatic tuning depending of the ship: mass, inertia, sas torque...

with this i should be able to use "persistant rotation mod", dost it exist yet?

As mentioned, MechJeb has a SAS functions that work well enough. And actually, RemoteTech has a type of SAS functionality as well, though probably not the type you're looking for. (Plus it's dependent on RemoteTech actual gameplay feature: comm links. You can lose ships very easily with RT.)

If you want something in the atmosphere, I recommend Pilot Assistant.

None of the above really "autotune" though.

And yes, there is a(n in active development) persistent rotation mod.

[sarbian]

MechJeb has an "attitude ajustment" window, where you can set some of its parameters, but AFAIK it's not a per-ship setting, and definetely not automatic based on mass.

You are wrong. Mechjeb2 SmartASS uses the vessel momentum and calculate the torque provided by the various ship system. The content of "attitude ajustment" should not be changed untless you really understand what you are doing.

[monstah]

You are wrong. Mechjeb2 SmartASS uses the vessel momentum and calculate the torque provided by the various ship system. The content of "attitude ajustment" should not be changed untless you really understand what you are doing.

Really? Well, nice to know. I'll stay away from it, then.

[Skalou]

thank you,

first i have to say there was a problem with the Claw stock bug fix mod, that was giving a delay to clutch gimbal and can lead to wobble, now updated.

for pilot assitant thank you, now i use it for long boring jet travel:wing leveller + alt control + KAC pause on alarm+ quick mute=u can go sleep.

there is also a modified sas but i'm not enought mad to use it and tune parameters for each stage of each vessel.

for mech jeb sorcery: me using this cheaty aimbot? me alive, never!! uuuh, considering it's the only one working great were is the DL link?

Edit:

what i need: http://blog.planete-nextgen.com/wp-content/uploads/2014/02/tapette-mouche-epee.jpg

what mech jeb is: http://us.123rf.com/400wm/400/400/vicnt/vicnt0907/vicnt090700006/5198698-jumping-t-90-tank-foto.jpg

Edited May 15, 2015 by Skalou

[Skalou]

No news on this?

Maybe my last post could be misunderstood after rereading, mechjeb is a really good mod but i don't want to use it now because i don't need most of the features (or there are in other smaller mod) . Maybe i will use it latter when i will be a vetteran bored to launch hundreds times the same fuel-resuplly ship, redundant thing, easy manoeuvres or when the piloting and trajectories won't be a difficulty factor.

For now i still use the stock SAS, but most of time only in vacuum , yesterday the SAS induced a resonance wobble that cutted the rocket in 2 parts during the launch! (when disable the rocket just roll a bit a do a nice gravity turn, still need some light manual correction however).

So what i'm still looking:

improved SAS in vaccum like described in first post:

-tune parameters to not over compensate (or really less)

-automatic tuning depending of the ship: momentum of inertia, reaction wheel torque...

-wobble fighting: detect and adjust to avoid resonances

atmosphere function: do the same with aero control parts, take care of wind speed, density,... there was these kinds of functions in FAR in 0.90 (now i use stock)

2 modes:

-Standard: use max 80% of the available controles to do the job but let 20% for manual adjusment.

-smooth: activable via shift key, objective: able to do a half turn in a defined time with smooth gradual limited torque to avoid wobble for spaghetti ships, save Ec, better looking manoeuvre.

transparent for the player, i don't want to tune all this PID or whatever parameters that are all intricated, it's possible by trial and error but there isn't easy rules to tune it, so it's long and not really fun for me, it's deffinitely a specialist task i will happily give to a program.

Maybe it's not an easy task (because the ship is not only one rigid part?) but it's just my point of view of gamer.

In waiting, is there a mod that allow to disable some axis on the SAS, so i can just activate it on the roll axis for launch?

Edited May 28, 2015 by Skalou

[sarbian]

You are asking for a mod that does exactly what MJ does. I don't think you really grasp the amount of code that it requires to duplicate those functionality.

I you don't want most of MJ tools then just disable them. Install MJ, module manager and create a text fie named basicMJ.cfg in GameData with that :

@PART[*]:HAS[@MODULE[ModuleCommand]]:Final
{
    %MODULE[MechJebCore]
    {     
        %name = MechJebCore
        %blacklist = MechJebModuleAscentGuidance MechJebModuleDockingGuidance MechJebModuleLandingGuidance MechJebModuleRCSBalancerWindow MechJebModuleRendezvousAutopilotWindow MechJebModuleRendezvousGuidance MechJebModuleRoverWindow MechJebModuleSmartASS MechJebModuleSmartRcs MechJebModuleSpaceplaneGuidance MechJebModuleThrustWindow MechJebModuleTranslatron
    }
}

[Warzouz]

BTW Sarbian, is there a way to use MJ features without adding the AR202 part to a ship ?

I've looked in the config files, but I didn't saw anythink which seemed related to that.

Thx

[sarbian]

Yes, there is

[Skalou]

Nice you have done this blacklist, so i'll give it a try ! (and i can't help trying again the other features on a sandbox )

Also i decided to take bull by horn and have a look at what is behind the scene, but unfortunately i didn't found informations on it in the MJ online manual, there is this but it's maybe outdated:

http://forum.kerbalspaceprogram.com/threads/49381-Mechjeb-How-to-make-SASS-chill-out-stop-wasting-RCS-and-shaking-things-apart

an interesting link to wikipedia: http://en.wikipedia.org/wiki/PID_controller

is your method is "Ziegler–Nichols method" or something like this?

i also play with pilot asistant, it's a different method? i see we can derictly modify the Kp,Ki and Kd

a nice picture from the wiki above to understand it for noob like me.

Thank you anyway to help me.

[sarbian]

Someone who use PiD for work wrote that part of code and I integrated it in MJ. I understand how they work but writing code that tune itself is not something I could easily do (not with the hundreds of other bugs I have to tend to in MJ).

I had some request to change the config UI but I did not get a better method to tune it so far.

The UI changed since that post but the underlying principle stayed the same.

Edit : It seems we use something related to the "Ziegler–Nichols method" but with different factors.

Edited June 1, 2015 by sarbian

[wasml]

regex has a PIP tuner - http://forum.kerbalspaceprogram.com/threads/117893

That what you were looking for?

[Skalou]

thank you wasml, the PID Tuner mod from regex you linked is minimalist and permit to tune himself the stock parameters, however pilot aids assistant include this feature too (and some other great i use). but the main problem is you have to know what you do (most of the time i make it worse), so i will try the MJ'one that include a self tuning method because it's simpler.

maybe latter i will try to come back to the classic PID parameters and try to tune it manualy because i understand a bit how it works now.

the target of this post was to find a better SAS you don't have to tune, for focus on the launch of this rocket and have fun!

Edited June 1, 2015 by Skalou

[Crzyrndm]

is your method is "Ziegler–Nichols method" or something like this?

i also play with pilot asistant, it's a different method? i see we can derictly modify the Kp,Ki and Kd

Mechjeb uses rotational acceleration to generate autotuning constants for it's PID controller (unmodified for the derivative constant, integrated once for proportional constant, integrated twice for the integral constant) with some additional constants to fine tune behaviour. It also modifies the error values based on the current rotational inertia instead of feeding the offset directly to the tuning loop among a few other little tricks.

// With some rearranging and substitution, MJ's autotuning looks like this. The only non-constant factor is Tf
// Tf is MOI/Torque, ie. 1/acceleration
double kpFactor = 1, kiFactor = 1, kdFactor = 1;
pid.Kp = kpFactor / (8.5 * Tf ^ 2);
pid.Ki = kiFactor / (72 * Tf ^ 3);
pid.Kd = kdFactor / (2 * Tf);

Pilot Assistant is raw tuning, there is no automated adjustment happening behind the scenes, which is why I highly recommend using Dynamic Deflection. The default tuning for Dynamic Deflection is probably closest to some form of linear inverse (1/x) but really, it's just interpolating between values that seemed to work.

Also, that graph is wrong. Increasing Kd should make the initial slope shallower, not steeper (the time to zero error increases with increasing Kd)

[rkman]

Maybe https://kerbalstuff.com/mod/765/PID%20Tuner ?